Longitudinal Body Mass Index Trajectories and Incident Chronic Kidney Disease in the General Population: Community-Based Cohort Study

Abstract

Objectives: Obesity is a risk factors for chronic kidney disease (CKD). However, the weight changes overtime and this was not well reflected in previous studies. Thus, this study performed to investigated the association body mass index (BMI) trajectories and incident CKD using group-based trajectory modeling. Subjects/Methods: 6,497 healthy subjects without medical comorbidities in the Korean Genome and Epidemiology Study were included in the analysis. Changes in BMI determined by trajectory modeling to accurately identify groups with similar trends of changes in BMI over time; decreasing BMI (slope of BMI per year (%)=-0.481, 95% CI, -0.482 to -0.480), stable BMI (slope=0.001, 95% CI, 0.001-0.002), and increasing BMI (slope=0.499, 95% CI, 0.498-0.501). The primary outcome of interest was incident CKD, which was defined as an estimated glomerular filtration rate of <60 mL/min/1.73m2 for two consecutive measurements. Results: During a 61,894.7 person-years, incident CKD occurred in 455 (7.0%) participants; 8.6, 6.5, and 8.2 per 1000 person-years across the trajectories, respectively ( P =0.005). The decreasing BMI group was associated with a 36% (hazard ratio [HR], 0.64; 95% CI, 0.48-0.85) and 29% (HR, 0.71; 95% CI, 0.52-0.98) lower risk of incident CKD in fully adjusted models compared with subjects with increasing BMI group. This association was evident particularly in overweight and obese subjects, while the significance was lost in underweight or normal weight group. Changes in BMI well correlated with changes in various metabolic parameters. Conclusions: Weight loss is associated with decreased risk of developing CKD in healthy individuals without comorbid diseases. Funding Statement: This study was supported by the Ministry for Health and Welfare, Republic of Korea [4845-301 and 4851-302], and also supported by a grant of the Korea Health Technology R&D Project through the Korea Health Industry Development Institute (grant number: HC15C1129). Declaration of Interests: No potential conflict interest relevant to this article were reported. Ethics Approval Statement: KOGES was conducted in accordance with the Declaration of Helsinki and approved by the Institutional Review Board of Yonsei University Health System’s Clinical Trial Center (approval number: 4-2016-0100).